A turbine engine driving a pair of contra-rotating propellers, for example, uses a reduction gear with an epicyclic gear train whereof the toothed outer annular gear rotates around the planet gear carrier while meshing on the planet gears. The lubrication of such equipment, all of the elements of which rotate, is a crucial aspect of its performance. If the reduction gear is not sufficiently lubricated, the friction between the teeth of the gears or at the bearings causes premature wear and decreased performance.
Since it is desirable to avoid this problem, the lubrication system is designed to send a significant oil flow rate, typically around 5000 liters per hour, to lubricate the reduction gear. The reduction gear is contained in one or several casings forming an oil enclosure comprising discharge means such as channels, which send the oil into the lubrication system. Nevertheless, if oil accumulates in the reduction gear, a so-called churning phenomenon occurs, which decreases the performance. It is therefore necessary for the oil discharge device to be sized to discharge this flow rate from the enclosure of the reduction gear.
Furthermore, the problem of mass being significant on an aircraft, it is necessary to prevent the recovery device around the reduction gear from having oil buildup zones, which may cause significant needless mass due to the oil flow rate to be discharged.
To that end, it is in particular necessary to have an effective oil recovery device so as to quickly return oil into the lubrication circuit and thus avoid oil retention there, which would increase the quantity of oil present in the circuit and therefore increase its mass.
Generally, as for example described in application FR-A1-2,987,402, a circular oil collection trough is placed around the orifices through which the oil leaving a rotary component is discharged. The walls of these troughs generally prevent lateral projections into the lubrication enclosure. However, they generally do not prevent part of the oil from falling back onto the reduction gear by gravity. This oil can cause excess oil in the reduction gear or be sprayed into the enclosure.
To avoid this, solutions are known, for example described in application FR-A1-3,020,658, to force recovery and avoid spraying, which creates an accumulation of oil in the enclosure before being recovered. The rotation is used to press the oil against the wall of the trough.
However, the rotation makes it more difficult to recover oil at the bottom of the device, since it tends to rise. An oil pocket is therefore created in the trough, and an oil accumulation detrimental to the mass of the system occurs.
There is therefore a need to improve the existing devices so that the oil recovery device around a rotary component, such as an epicyclic reduction gear, for example, contains as little oil as possible and effectively steers a significant oil flow rate toward the lubrication circuit.